A sterile rod made of metal or other material which, when inserted into the intramedullary canal of the tibia, acts to immobilize by holding the ends of a fractured bone in position to promote healing. The device may also be used to support the bone in the presence of a pathological condition, or for knee arthrodesis. The device may be a locked or unlocked model, and possess components to assist fixation of more proximal or distal conditions. This is a single-use device.